I’ve done a couple of tests and in 1h I can get 1 big treasures (450 score) or ~500 gold bars(15000 score) from farming obsidian on Exiled Lands, in the volcano biome.
Both are shared resources and you have to compete for them. Big tresures can be brought back home through a teleport, so having to carry them is not really a downside.
Overall, it’s quite obvious that big treasures need a boost in score to compete with the other method of getting treasure score.
Another option would be to devalue silver and gold even more, so both methods are worth the same time investment.
With big treasures taking up space in my base, farming gold remains by far the best method of accruing treasure score, to the point where I’m no longer interested in this treasure hunt anymore.